1. Field of the Invention
This invention relates to a selectively operable hold-open device for use with a conventional door closer. More specifically, the invention relates to a hold-open device for a swinging door, the device adapted to be made effective by power means such as a solenoid and rendered ineffective permitting the door to close either by de-activation of the same power means or by being overcome by forcible manual closing of the door.
2. Description of the Prior Art
In the prior art there are a number of devices adapted to be used with the single operating arm of a conventional door closer mounted on a swinging door for the purpose of holding the door open. Typically, such devices are used in hospitals, for instance, whereby the door may be manually held open by the device until its power means are actuated to release the door to permit it to close. Such an arrangement has been used in situations wherein in the event of fire, for instance, the door to a patient's room is automatically closed. Examples of the prior art include the U.S. Pat. No. 3,771,823, issued to Schnarr, wherein a hooked shoe rides in a track on the door frame and is connected to a door closer mounted on a door. The hooked shoe in the hold-open position is engaged by a pair of mating hooks which are solenoid-actuated and releaseably hold the shoe with the door in the hold-open position. Other examples of such hold-open devices are found in U.S. Pat. No. 3,164,404, issued Jan. 5, 1965 to Arnold, U.S. Pat. No. 3,926,461, issued Dec. 16, 1975 to D'Hooge.